Length measuring device for automatic folders



22,-, w. B. G. CRAN 3,162,755

vmsumuc DEVICE FOR AUTOMATIC FOLDERS IUENGWEH tFilefl April 35%? 4Sheets-Sheet l HINVEFIIOR;

WILL IAN 8.16. 0 WA u :sBY

Dec. 22, 1964 w. B. G. CRAN 3,162,765

LENGTH MEASURING DEVICE FOR AUTOMATIC FOLDERS 4 Sheets-Sheet 2 FiledApril 10, 1962 INVENTORZ WILLIAM A GRAN A770? NE Y3 w. a 5. GRAN3,162,765

LENGTH MEASURING DEVICE FOR AUTOMATIC FOLDERS Dec. 22, 1 964 4Sheets-Sheet 5 Filed April 10, 1962 INVENTOR: /uunm CH N w. B. G. GRAN3,162,765

LENG IZHZ MEASURING DEVICE FOR AUTOMATIC FOLDERS 4 Sheets-Sheet 4 Dec.22, 1964 Filed April 10, 19623 INVENTORZ A/ILLIAM B -0 BY MJQM W 'WUnited States Patent Qfifice 3,162,7h Patented Dec. 22, 1964- 3,162,765LENGTH MEASURING DEVICE FOR AUTOMATIC FGLDERS William Broadbent GordonCran, Den'oy Dale, near Huddersfield, England, assignor to ThomasBroadbent & Sons Limited, Huddersfield, Yorkshire, England Filed Apr.1t), 1962, Ser. No. 186,450 Claims priority, application Great Britain,Apr. 11, 1961, 12,937/61; Feb. 14, 1962, 5,596/62 16 Claims. (Cl.250-223) The present invention relates to timing devices for monitoringthe progress of articles travelling in open form along a given path andeach of which changes speed, earlier or later depending upon its length,at a time when its trailing end passes a given point in said path. Theinvention is particularly applicable to the monitoring of the progressof articles travelling from an ironing machine to a folding device forthe purpose of ensuring that the article is folded by the folding deviceat a given locality with respect to its length.

According to the present invention a timing device for monitoring theprogress of articles travelling in open form along a given path and eachof which changes from a first speed to a second speed, earlier or laterdepending upon its length, at a time when its trailing end passes agiven point in said path, comprises a controller adapted to initiate asignal when it has moved through a given amplitude of movement, means todrive the controller through an initial portion of said given amplitudeat a speed in prescribed ratio to the first speed of the article duringthe period when the article moves past said given point, and means todrive the controller at a speed in given ratio, higher than saidprescribed ratio, to the second speed of the article immediately afterthe trailing end of the article moves beyond said given point and untilthe controller completes its movement through the remainder of saidgiven amplitude to achieve the result that irrespective of the length ofthe article a signal is initiated by the controller when a point on thearticle in advance of its trailing end by a distance equal to a fractionof its length represented by said prescribed ratio divided by said givenratio reaches a second given point in the path of the article beyondsaid given point by a distance equal to said amplitude of the controllerdivided by said given ratio.

According to another aspect of the invention a timing device formonitoring the progress of articles travelling in open form along agiven path at speeds governed respectively by a first driving means anda second driving means and the speed of each of which becomes subject tothe second driving means earlier or later depending upon its length whenits trailing end leaves said first driving means comprises a controlleradapted to initiate a signal when it has moved through a given amplitudeof movement, means to drive the controller through an initial portion ofsaid given amplitude of movement at a speed in prescribed ratio to thespeed of the first driving means during the period that the articlemoves past a given point adjacent to the position Where the trailing endof the article leaves said first driving means, and means to drive thecontroller at a speed in given ratio, higher than said prescribed ratio,tothe speed of the second driving means immediately after the trailingend of the article leaves said first driving means and until thecontroller completes its movement through the remainder of said givenamplitude to achieve the result that irrespective of the length of thearticle a signal is initiated by the controller when a point on thearticle in advance of its trailing end by a distance equal to a fractionof its length represented by said prescribed ratio divided by said givenratio reaches a second given point in the path of the article beyondsaid given point by a distance equal to said amplitude of the controllerdivided by said given ratio.

The controller may be driven through the said initial portion of itsamplitude of movement by rotatable means in the path of the articlepositioned adjacent to said given point and adapted to be engaged anddriven by the article.

In one form of construction of timing device according to the inventionthe distance between said given point and said second given point may beequal to the amplitude of movement of the controller in which case thecontroller should be driven through said initial portion of itsamplitude of movement at a fraction of the speed of the article equal tothe aforesaid fraction of the length of the article from its trailingend. The amplitude of the controller however may be different from butin a fixed proportion to the distance between said given point and saidsecond given point in which case the speeds at which the controller isdriven should be modified in accordance with said fixed proportion.

The controller may be driven through said initial portion of itsamplitude of movement at a speed in prescribed ratio to or at saidprescribed fraction of the speed of the article or of said first drivingmeans through a mechanical power transmission means and through areleasable clutch. The controller may be driven through the remainder ofsaid given amplitude of movement at the speed of the article or at aspeed in said given ratio to the speed of the article or of said seconddriving means by an electric motor and through a clutch. Said clutchesare preferably electro-magnetically operable. Alternatively electricaldriving links may be provided for driving the controller through saidinitial portion and through said remainder of said given amplitude ofmovement. Thus the controller may be driven by an electric motor fedwith pulses at rates proportional to the speeds of the article or ofsaid first and second driving means.

The invention includes the combination of an ironing machine, a foldingdevice and a conveyor extending from the ironing machine to the foldingdevice and a timing device as above set forth for monitoring theprogress of the article from the ironing machine to a predeterminedposition between the ironing machine and the folding device whereby toenable the folding device to be brought into operation on the article ata given production of its length from one end thereof by timing theoperation of the folding device in relation to said signals to the speedof the conveyor.

In one form of construction of the invention a photoelectric receiver isarranged at one end of a folder conveyor immediately adjacent to theexit of an ironing machine. A controller in the form of a rotatable camis arranged to operate a micro-switch on movement through a prescribedamplitude preferably 360 and is driven through gears by a roller whichis arranged immediately above the extreme end of the folder conveyoradjacent to the ironing machine and which is driven by the article as itemerges from the ironing machine, the gear ratio between the roller andthe cam being such that the cam is driven at a prescribed fraction, e.g.one half, of the speed of the article,

The photo-electric receiver controls a clutch for drivably connectingthe cam to the roller. The cam is also drivable at the speed of thefolder conveyor either by an electric motor which is synchronized withthe speed of the conveyor, or through suitable transmission means by thefolder conveyor itself. The driving of the cam at the speed of thefolder conveyor is afiected by means of a clutch also under the controlof the photo electric receiver, the arrangement being such that whenlight projected towards the photo electric receiver is obstructed by anarticle passing from the ironer to said roller the cam is driven by theroller through said first mentioned clutch but when the article hasemerged from the ironer to enable the light beam to impinge on the photoelectric receiver said first mentioned clutch is released and saidsecond mentioned clutch engaged to cause the cam to be driven at thespeed of the folder conveyor. Since the cam is driven by the roller fora period corresponding to the length of the article and since duringthis period the cam is driven at a fraction, e.g. half the speed of thearticle and since the cam is thereafter driven at the speed of thearticle it follows that irrespective of the length of the article themicro-switch will be operated when the midlength of the article hasreached a given point spaced from the roller by a distance equal to theamplitude movement of the cam.

The controller may be driven from said rotatable means by an electricallink instead of a mechanical power transmission means as describedabove. The provision of an electrical link enables the clutch employedin the mechanical connection to be replaced by a switch and relay.

The invention will be further described by way of example with referenceto the accompanying drawings in which:

FIG. 1 is a diagrammatic side elevation of one embodiment of theinvention,

FIG. 2 is a diagrammatic plan view of the embodiment shown in FIG. 1, 7

FIG. 3 is a diagrammatic side elevation of a second embodiment of theinvention,

FIG. 4 is a schematic diagram illustrating the driving of the controllerby electrical links,

FIG. 5 is a side view of a further embodiment of the invention, and

FIG. 6 is a fragmentary sectional view corresponding to FIG. 5.

Referring to the FIGS. 1 and 2 an article emerging from an ironer 1passes along a folder conveyor 2 and drop between a fold blade 3 and niprollers 4 situated beneath the delivery end of the folder conveyor. At acorrect moment an air cylinder 5 or other suitable means actuates thefold blade 3 to push the article between the nip rollers. The foldedarticle is then delivered out of the apparatus on a second conveyor 6leading for example to a stacking device or to a delivery table or to afurther folding mechanism.

The article moves at the speed of the ironer 1 until its trailing endclears the ironer and thentravels at the higher speed of the folderconveyor. Above the folder conveyor at the end adjacent to the ironer,is a roller 7 which drives a gear wheel 8 through a system ofintermediate gears 9. A cam 10 coaxial with this gear wheel 8 18connected or disconnected to the gear wheel 8 through an electromagneticclutch 11 (FIG. 2). Also coaxial with the gear wheel 8 and the cam 10 isan electric motor 12 which may be connected or disconnected to the camthrough a second electromagnetic clutch 13.

The electric motor 12 is of constant speed such that when it drives thecam 10, the peripheral speed of the latter 1s exactly the same as thespeed of the folder conveyor 2. When the cam is driven through the gearsby the roller 7 the peripheral speed of the cam is a certain fraction ofthe peripheral speed of the roller depending upon the diameters andnumbers of gears 9 between the cam 10 and the roller 7. For the purposeof the present example, the peripheral speed of the cam 10 will be takenas half that of the roller 7.

Once every complete revolution the cam 10 operates a mlcro-switch 14. Inline with the roller 7 is a switch re (FIG. 2), preferably aphoto-electric receiver and light source so arranged that as an articlereaches the conveyor 2 it cuts the light beam impinging on the receiver.The photo-electric receiver is adjustable longitudinally 1n thedirection of travel of the article so that the point at whlch theleading end of the article cuts the beam (and When the trailing endleaves it) can be adusted.

Dimensions are arranged so that the length of the folder conveyor isapproximately 60% Of the length of the longest article to be folded, andthe circumference of the cam is approximately of the length of thelongest article.

The operation of the device is as follows: When no article is passing,the roller 7 is driven by the folder conveyor 2 and the gear wheel 8 isdisconnected from the cam which is at rest, with the micro-switch 14inoperative. As an article emerges from the ironer 1 it is nippedbetween the roller 7 and the folder conveyor 2. As long as part of thearticle is in the ironer, the article moves at the speed of the ironer.On entering the nip, the leading end of the article interrupts the lightbeam striking the photo-electric receiver 15 and this causesenergisation of the electromagnetic clutch 11 so that the cam 10 is nowdriven by the roller 7. This, in turn, operates the micro-switch 14which starts the motor 12.

The roller 7 continues to drive the cam 10 until the trailing end of thearticle emerges from the ironer 1 and clears the photo-electric receiver15. When this happens the roller will have rotated proportionally to thelength of the article and the recess on the cam will have moved througha distance equal to one half of the length of the article. When thetrailing end of the article clears the photo-electric receiver 15 theimpingement of the light beam on the receiver causes the electromagneticclutch 11 to be disengaged and the second electromagnetic clutch 13 tobe engaged so that the cam 10 is now rotated by the motor 12 but at aspeed equal to that of the folder conveyor. When the cam 16) hascompleted one revolution, the micro-switch 14 will again be operated andthe midlength of the article to be folded will have reached a fixedpoint on the folder conveyor in advance of the switch 15 by a distanceequal to the amplitude of the cam i.e. its peripheral length. This pointis marked X on FIG. 1 and holds good for any length of article. When thecam 10 has completed one revolution the motor 12 stops and a time delayrelay is operated to actuate the fold blade 3 after a preset timeinterval determined by the distance from the point X to the nip rollers4 and the time taken by the article to travel this distance. Theoperation of the fold blade 3 (or alternatively the operation of themicro-switch 14) disconnects the electromagnetic clutch 13 and resetsthe device for the next cycle of operation.

As in practice, articles follow each other in rapid succession from theironer, it will be apparent that at least two devices are needed with anautomatic cycling switch so that succeeding articles are measured ondifferent devices.

The example given is for folding articles in half but by suitablearrangement of the gear train 9 an article can be folded into a desiredfraction of its length.

The embodiment illustrated in FIG. 3 operates in a similar manner tothat already described. The cam 10, operating a micro-switch 14 anddriven by gear wheels 9, has however been replaced by a disc 16 drivenby a system of pulleys 17. A hole 18 is bored through the disc 16 at apoint near its periphery and a photo-electric receiver 19 and a lightsource 20 are located on opposite sides of the disc 16. When the disc 16is at rest, prior to the passing of an article beneath the roller 7, thelight beam passes through hole 13 and impinges on the photoelectricreceiver 19. As soon as the disc starts to rotate the beam is cut off,and is not restored until the disc has completed one revolution and thehole 18 has returned opposite to the light source. This photo-electricreceiver 19 and light source 20 replaces and performs the same functionas the micro-switch 14 of the previous embodiment. The relationshipbetween the peripheral speeds of the disc 16 and the roller 7 aredetermined by their diameters and the pulley system used.

The device illustrated in FIG. 4 comprises an endless conveyor 31, afold blade 32 and a nip roller 33. A roller 34 is situated adjacent theend of the conveyor 31 remote from fold blade 32. This roller is drivenby the conveyor 31 or by an article to be folded passing between it andthe conveyor 31. The roller 34 drives a tachogenerator which ispreferably located inside the roller 34 and whose presence is indicatedby the reference 35. A photo-electric unit 36 is also positionedadjacent the end of the conveyor 31 and the roller 34. Thetacho-generator 35, which is preferably of the permanent magnet type, iselectrically connected to a pulse shaping and amplifying circuit 37,which is connected in turn through a switch 38 to a synchronous motor 39which drives a cam 40. The present invention thus provides a synchronouselectrical link between the roller 34 and the cam 40 instead of amechanical connection as described with reference to FIGS. 1, 2 and 3.The synchronous motor 39 is also connected electrically to a secondsupply source through a relay 4-1 and a switch 42. The cam 40 isarranged to actuate a micro-switch 43.

The device operates in the following manner. An article to be folded onentering between the conveyor and the roller 34 cuts across a light beamimpinging on the photo-electric unit 36. The article moving between theconveyor 31 and the roller 34 directly drives the roller 34 and hencethe tacho-generator 35. The tacho-generator produces voltage pulses at arate proportional to a fraction of the speed of the article, and willproduce on pulse per unit length of the articles independent of thespeed of the article. For the sake of illustration voltage pulses areproduced in the present example at a rate proportional to half of thespeed of the article to result in the article being folded in half.

The photo-electric unit 36, on actuation by the leading edge of thearticle passing between the roller 34 and the conveyor 31 and cuttingacross the light beam, operates switch 38 so connecting the pulseshaping and amplifying circuit 37 to the synchronous motor 39. Thus thesynchronous motor 39 is driven from the tacho-generator 35 while thearticle passes between the nip formed by the roller 34 and the conveyor31. This causes the cam 40 to rotate at a peripheral speed equal to halfof the speed of the article. As soon as the cam 40 starts to rotate,micro-switch 43 is actuated and this in turn closes relay 41 in theleads to the external supply circuit.

When the trailing edge of the article clears the nip between the roller34 and the conveyor 31 the light beam re-impinges on the photo-electricunit 36. This causes the switch 33 to open and at the same time closesswitch 42. The pulse shaping and amplifying circuit 37 is therefore cutoff from the synchronous motor 39 which is now driven by the externalpower supply source as both the relay 41 and the switch 42 are closed.The external power supply source may be the same as that driving theconveyor 31. The cam 46 now rotates at a peripheral speed equal to thespeed of the conveyor until it completes one full revolution. Oncompleting the full revolution the microswitch 43 is again actuated bythe cam 48 and this causes the relay 41 to be opened to disconnect thesynchronous motor from the external supply source.

By the time the cam 40 has completed a full revolution, the mid lengthof the article to be folded will have reached a point X on the folderconveyor 31. The distance from the nip between the roller 34 and theconveyor 31 to the point X is equal to the circumference of the cam 40and the mid point of an article will always coincide with the point X onthe conveyor 31 irrespective of the length of the article to be folded.When the mid-point of the article has reached the point X a time relayis operated to actuate the fold blade 32 after pre-set intervaldetermined by the distance from the point X to the nip rollers 33 andthe time taken by the article to travel this distance. The operation ofthe fold blade 32 re-sets the device for the next cycle of operation.The folded article on emerging from the nip rollers 33 is carried awayon a conveyor 44.

The above example refers to folding an article in half, but by suitablechoice of tacho-generator to produce volt- 6 age pulses at a rateproportional to any fraction of the speed of the article the article canbe folded at such a fraction of its length.

In the above example after the article has cleared roller 34, thesynchronous motor 39 is supplied by a power supply having the samefrequency as that delivered to the motor driving the conveyor 31. As analternative to this method a second tacho-generator driven by theconveyor 31 may be used to provide the required pulse rate. This pulserate has to be shaped and amplified by a circuit similar to the circuit37 before being supplied to the synchronous motor 39.

Referring now to FIGS. 5 and 6 a roller 51 located on a conveyor 52 anddrivable by an article passing therebetween is connected through a geartrain 53 to a timing device 54.

As may be seen from FIG. 6 the timing device 54 comprises a pair oftimers 55 arranged side by side. Each timer 55 comprises a shaft 56having a cam disc 57 at one end. Three sleeves 58, 59 and 60 are locatedon each shaft 56; sleeves 58 and 60 are rotatably mounted on the shaft56 whilst the centre sleeve 59 is rigidly fixed or splined to the shaft.A pair of electro-magnets 61 and 62 encircle the sleeves. The sleeve 58carries a gear wheel 63 which is at the end of the gear train 53 linkingthe sleeve 58 to the roller 51. The sleeve 60 carries a gear wheel 64which meshes with another gear wheel 65 mounted on a shaft 66 (FIG. 5).The shaft 66 is driven at a speed proportional to that of the conveyor52, either by a separate motor (not shown) or by a drive taken from theconveyor 52 itself.

A pawl 67 (FIG. 5) engages in a notch 68 in the periphery of the camdisc 57. The pawl 67 is raised on energisation of a solenoid 69 to allowrotation of the disc 57.

In operation, when an article passes between the roller 51 and theconveyor 52 light falling on a photo-electric receiver 70 from a lightsource 71 is interrupted and electromagnet 61 and solenoid 69 areenergised. Energisetion of the electro-m-agnet 61 causes sleeves 58 and59 to be brought into engagement so causing rotation of the disc 57 asthe pawl 67 is now lifted out of the notch 68. Disc 57 is thereforedriven from the roller 51 through the gear train 53 such that the speedof rotation of the disc 57 is a certain fraction of the speed ofrotation of disc 51. As before, this fraction will be taken as a halffor the sake of example only.

When the trailing edge of the article clears the photoelectric receiver70 and light source 71, electromagnet 61 and solenoid 69 arede-energised. Pawl 67 now drops on to the surface of the disc 57 and atthe same time electromagnet 62 is energised. Energisation ofelectromagnet 62 causes sleeve 59 to be moved out of engagement withsleeve 58 and into engagement with sleeve 60. Disc 57 is now driven atthe same speed as the conveyor 52 through the gear wheel 64, sleeve 60,and shaft 56.

Upon completion of a single revolution of the disc 57, the pawl 67 dropsback into the notch 68. This causes the de-energisation of theelectromagnet 62 and a time delay is actuated to operate a folder bladeafter a set time interval.

As articles generally follow one another in quick succession along theconveyor 52, it is necessary to have at least two timing devices inoperation. This is achieved, as shown in FIG. 6, by duplicating themechanism already described. Gear wheel 63 is mounted on sleeve 58 whichin turn is rotatably mounted on shafts 56 and 72. The shafts areseparated by a gap 73 so that the shafts can rotate independently of oneanother.

Although the invention has been particularly described in combinationwith an ironing machine it may of course be employed in othercombinations. For example the conveyor 2 may receive articles from afeeding conveyor running at a slower speed than its own. Moreover theinvention can be used in other combinations than with a folding device.

I claim:

1. A proportional length measuring device for monitoring the progress ofarticles travelling in open form along a given path and each of whichchanges from a first speed to a second speed during its monitoredprogress comprising a controller. adapted to initiate a signal when itis moved through a given amplitude of movement, rotatable means in thepath of the article adapted to be engaged and driven by the article andto drive the controller through an initial portion of said givenamplitude at a speed in prescribed ratio to the speed of the article andmeans to drive the controller at a speed in given ratio, higher thansaid prescribed ratio, to the second speed of the article immediatelyafter the trailing end of the article moves out of contact with saidrotatable means and until the controller completes its movement throughthe remainder of said given amplitude to achieve the result thatirrespective of the length of the article the signal is initiated by thecontroller when a point on the article in advance of its trailing end bya distance equal to a fraction of its length represented by saidprescribed ratio divided by said given ratio reaches a point in the pathof the article beyond said rotatable means by a distance equal to saidamplitude of the controller divided by said given ratio.

2. A proportional length measuring device according to claim 1comprising mechanical power transmission means and releasable clutchmeans for transmitting drive to said controller through said initialportion of its amplitude of movement.

3. A proportional length measuring device according to claim 1characterized by an electric motor and a releasable clutch for drivingsaid controller through said remainder of its amplitude of movement.

4. A proportional length measuring device according to claim 1comprising electrical links for transmitting drive to the controllerthrough respectively said initial portion of its amplitude in saidprescribed ratio to the speed of the article and through said remainderof its amplitude in said given ratio to the speed of the article.

5. A proportional length measuring device according to claim 1comprising an electric motor for driving said controller fed with pulsesat rates proportional to the speeds of the article.

6. A proportional length measuring device according to claim 1comprising an electric motor for driving the controller, atachogenerator adapted to feed pulses to said motor and rotatable meansengageable by the article for driving the tachogenerator.

7. A proportional length measuring device according to claim 1comprising switch means located substantially at said rotatable means toinitiate the driving of the controller at one speed through said initialportion of said given amplitude when the leading end of the articlereaches said rotatable means and subsequently to discontinue the drivingof the controller at said one speed and to initiate the driving thereofat a different speed through the remainder of said given amplitude whenthe trailing end of the article moves beyond said rotatable means.

8. A proportional length measuring device according to claim 7comprising switch means in the form of a light source and photo-electricreceiver.

9. A proportional length measuring device according to claim 7comprising a second switch operated by the controller when it completesits movement through said given amplitude.

10. A proportional length measuring device according to claim 1comprising two controllers, switch means located substantially at saidrotatable means to initiate be driving of said controllers alternatelyat one speed through said initial portion of the given amplitude andthen at a different speed through the remainder of the given ampli-.tude, and individual switch means associated one with each of thecontrollers each adapted to be operated by its controller as thecontroller completes its movement through its given amplitude.

11. A proportional length measuring device for monitoring the progressof articles travelling in open form along a given path at speedsgoverned respectively by a first driving means and a second. drivingmeans and the speed of each of which becomes subject to the seconddriving means earlier or later depending upon its length when itstrailing end leaves said first driving means, comprising a controlleradapted to initiate a signal when it has moved through a given amplitudeof movement, rotatable means in the path of the article adapted to beengaged and driven by the article and to drive the controller through aninitial portion of said amplitude at a speed in prescribed ratio to thespeed of the driving means during the period that the article moves pasta given point adjacent to the position where the trailing end of thearticle leaves said first driving means, and means to drive thecontroller at a speed in given ratio, higher than said prescribed ratio,to the speed of the second driving means immediately after the trailingend of the article leaves said rotatable means and until the controllercompletes its movement through the remainder of said given amplitude toachieve the result that irrespective of the length of the article asignal is initiated by the controller when a point on the article inadvance of its trailing end by a distance equal to a fraction of itslength represented by said prescribed ratio divided by said given ratioreaches a second given point in the path of the article beyond saidgiven point by a distance equal to said amplitude of the controllerdivided by said given ratio.

12. A proportional length measuring device for monitoring the progressof articles travelling in open form along a given path and each of whichchanges from a first speed to a second speed earlier or later dependingupon its length at a time when its trailing end passes a given point insaid path, comprising a controller adapted to initiate a signal when ithas moved through a given amplitude of movement, rotatable means in thepath of the article positioned adjacent to said given point adapted tobe engaged and driven by the article and to drive the controller throughan initial portion of said given amplitude at a prescribed fraction ofthe speed of the article during the period that the article moves pastsaid rotatable means and means for driving the controller at the secondspeed of the article immediately after the trailing end of the articlemoves beyond said rotatable means and until the controller completes itsmovement through the remainder of said given amplitude to achieve theresult that irrespective of the length of the article a signal isinitiated by the controller when a point on the article in advance ofits trailing end by a distance equal to said prescribed fraction of itslength reaches a second given point in the path of the article.

13. A proportional length measuring device according to claim 12 inwhich said second given point is located beyond said first given pointby a distance equal to the amplitude of the controller.

14. A proportional length measuring device according to claim 13 inwhich the amplitude of the controller is different from but in a givenproportion to the distance between said given point and said secondgiven point and the speeds at which the controller is driven aremodified in accordance with said fixed proportion.

15. A proportional length measuring device for monitoring the progressof articles travelling in open form along a given path each of whichchanges from a first speed to a second speed earlier or later dependingupon its length when its trailing end passes a given point in said pathcomprising a controller adapted to initiate a signal when it has movedthrough a given amplitude of movement, rotatable means in the path ofthe article adapted to be engaged and driven by the article and to drivethe controller through an initial portion of said given amplitude at aspeed in prescribed ratio to the speed of the article during the periodwhen the article moves past said given point, means to drive thecontroller at a speed in given ratio, higher than said prescribed ratio,to the speed of the article immediately after the trailing end of thearticle moves beyond said given point and until the controller completesits movement through the remainder of said given amplitude, switch meanslocated substantially at said given point to initiate the driving of thecontroller at one speed through said initial portion of said givenamplitude when the leading end of the article reaches said given pointand subsequently to discontinue the driving of the controller at saidone speed andto initiate the driving thereof at a dilferent speedthrough the remainder of said given amplitude when the trailing end ofthe article moves beyond said given point and a second switch operatedby the controller when it completes its movement through said givenamplitude.

16. The combination of an ironing machine for articles of laundryflatwork, a folding device, conveyor means between the ironing machineand folding device and a proportional length measuring device formonitoring the movement of articles from the ironing machine to thefolding device, said measuring device having a controller adapted toinitiate a signal when it has moved through a given amplitude ofmovement in which the conveyor means conveys the articles at a speedhigher than that of the movement of the articles through the ironingmachine so that the speed of each article changes from a first speed toa second higher speed at an instant when its trailing end leaves theironing machine, which controller is driven by a rotatable means whichis located near to where the article leaves the ironing machine andwhich is adapted to be engaged and driven by the article and thus todrive the controller through an initial portion of said given amplitudeat a speed in prescribed ratio to the first speed of the article.

References Cited by the Examiner UNITED STATES PATENTS 2,743,920 5/56Petre 27080 2,774,592 12/56 Kagan 270-81 2,858,129 10/58 Buss 270812,871,010 1/59 Likens 27081 2,942,874 6/60 Hajos 27083 RALPH G. NILSGN,Primary Examiner.

WALTER STOLWEIN, Examiner.

1. A PROPORTIONAL LENGTH MEASURING DEVICE FOR MONITORING THE PROGRESS OFARTICLES TRAVELLING IN OPEN FORM ALONG A GIVEN PATH AND EACH OF WHICHCHANGES FROM A FIRST SPEED TO A SECOND SPEED DURING ITS MONITOREDPROGRESS COMPRISING A CONTROLLER ADAPTED TO INITIATE A SIGNAL WHEN IT ISMOVED THROUGH A GIVEN AMPLITUDE OF MOVEMENT, ROTATABLE MEANS IN THE PATHOF THE ARTICLE ADAPTED TO BE ENGAGED AND DRIVEN BY THE ARTICLE AND TODRIVE THE CONTROLLER THROUGH AN INITIAL PORTION OF SAID GIVEN AMPLITUDEAT A SPEED IN PRESCRIBED RATIO TO THE SPEED OF THE ARTICLE AND MEANS TODRIVE THE CONTROLLER AT A SPEED IN GIVEN RATIO, HIGHER THAN SAIDPRESCRIBED RATIO, TO THE SECOND SPEED OF THE ARTICLE IMMEDIATELY AFTERTHE TRAILING END OF THE ARTICLE MOVES OUT OF CONTACT WITH SAID ROTATABLEMEANS AND UNTIL THE CONTROLLER COMPLETES ITS MOVEMENT THROUGH THEREMAINDER OF SAID GIVEN AMPLITUDE TO ACHIEVE THE RESULT THATIRRESPECTIVE OF THE LENGTH OF THE ARTICLE THE SIGNAL IS INITIATED BY THECONTROLLER WHEN A POINT ON THE ARTICLE IN ADVANCE OF ITS TRAILING END BYA DISTANCE EQUAL TO A FRACTION OF ITS LENGTH REPRESENTED BY SAIDPRESCRIBED RATIO DIVIDED BY SAID GIVEN RATIO REACHES A POINT IN THE PATHOF THE ARTICLE BEYOND SAID ROTATABLE MEANS BY A DISTANCE EQUAL TO SAIDAMPLITUDE OF THE CONTROLLER DIVIDED BY SAID GIVEN RATIO.